Commited BeOS changes by Richard Shepherd and Tony Castley.

   include/video_output.h
    * Added boolean_t b_YCbr to vout_thread_s structure to flag YUV-YCbCr
      decoding needed instead of YUV-RGB
    * Will be removed later when video_output.c rewritten

   src/video_output.c
    * vout_CreateThread() initialises b_YCbr to zero

   plugins/beos/*
    * New BeOS video plugin that supports hardware overlays and new
      MediaPlayer compatible interface

   plugins/*
    * Added YUV-YCbCr transforms